I’ve been using Citadel paints to paint my models, but recently started searching for a cheaper base coat/primer.
I picked up with some Daler Rowney Graduate Acrylic (http://www.daler-rowney.com/graduate-acrylic) in Netural Grey and Mars Black over the weekend.
I am really happy with the coverage the black gives, even on white filament. The grey is so-so; it needs 2 coats.
I print most of the time with 0.1mm layer height and almost never sand the models. I’ll post some pics here once I get home.